<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Array Cardio 💪</title>
</head>
<body>
  <p><em>Psst: have a look at the JavaScript Console</em> 💁</p>
  <script>
    // Get your shorts on - this is an array workout!
    // ## Array Cardio Day 1

    // Some data we can work with

    const inventors = [
      { first: 'Albert', last: 'Einstein', year: 1879, passed: 1955 },
      { first: 'Isaac', last: 'Newton', year: 1643, passed: 1727 },
      { first: 'Galileo', last: 'Galilei', year: 1564, passed: 1642 },
      { first: 'Marie', last: 'Curie', year: 1867, passed: 1934 },
      { first: 'Johannes', last: 'Kepler', year: 1571, passed: 1630 },
      { first: 'Nicolaus', last: 'Copernicus', year: 1473, passed: 1543 },
      { first: 'Max', last: 'Planck', year: 1858, passed: 1947 },
      { first: 'Katherine', last: 'Blodgett', year: 1898, passed: 1979 },
      { first: 'Ada', last: 'Lovelace', year: 1815, passed: 1852 },
      { first: 'Sarah E.', last: 'Goode', year: 1855, passed: 1905 },
      { first: 'Lise', last: 'Meitner', year: 1878, passed: 1968 },
      { first: 'Hanna', last: 'Hammarström', year: 1829, passed: 1909 }
    ];

    const people = ['Beck, Glenn', 'Becker, Carl', 'Beckett, Samuel', 'Beddoes, Mick', 'Beecher, Henry', 'Beethoven, Ludwig', 'Begin, Menachem', 'Belloc, Hilaire', 'Bellow, Saul', 'Benchley, Robert', 'Benenson, Peter', 'Ben-Gurion, David', 'Benjamin, Walter', 'Benn, Tony', 'Bennington, Chester', 'Benson, Leana', 'Bent, Silas', 'Bentsen, Lloyd', 'Berger, Ric', 'Bergman, Ingmar', 'Berio, Luciano', 'Berle, Milton', 'Berlin, Irving', 'Berne, Eric', 'Bernhard, Sandra', 'Berra, Yogi', 'Berry, Halle', 'Berry, Wendell', 'Bethea, Erin', 'Bevan, Aneurin', 'Bevel, Ken', 'Biden, Joseph', 'Bierce, Ambrose', 'Biko, Steve', 'Billings, Josh', 'Biondo, Frank', 'Birrell, Augustine', 'Black, Elk', 'Blair, Robert', 'Blair, Tony', 'Blake, William'];

    // Array.prototype.filter()
    // 1. Filter the list of inventors for those who were born in the 1500's
    const fifteens = inventors.filter(inventor => (inventor.year >= 1500 && inventor.year < 1600));
    console.table(fifteens);

    // Array.prototype.map()
    // 2. Give us an array of the inventors' first and last names
    const names = inventors.map(inventor => `${inventor.last} ${inventor.first}`);
    console.log(names)

    // Array.prototype.sort()
    // 3. Sort the inventors by birthdate, oldest to youngest
    const births = inventors.sort((last, next) => {
      return last.year > next.year ? 1: -1;
    });
    console.table(births);

    // Array.prototype.reduce()
    // 4. How many years did all the inventors live?
    const years = inventors.reduce((count, inventor)=>{
      count += inventor.passed - inventor.year;
      return count;
    }, 0);
    console.log('all live: ' + years);

    // 5. Sort the inventors by years lived
    const yearLived = inventors.sort((last, next) => {
      const lastLived = last.passed - last.year;
      const nextLived = next.passed - next.year;
      return lastLived > nextLived ? 1 : -1;
    })
    console.table(yearLived);

    // 6. create a list of Boulevards in Paris that contain 'de' anywhere in the name
    // https://en.wikipedia.org/wiki/Category:Boulevards_in_Paris


    // 7. sort Exercise
    // Sort the people alphabetically by last name  按字母排序
    const alphas = people.sort((last, next) => {
      const [alast, afirst] = last.split(', ');
      const [blast, bfirst] = next.split(', ');
      return alast > blast ? 1 : -1;
    })
    console.log(alphas)

    // 8. Reduce Exercise
    // Sum up the instances of each of these
    const data = ['car', 'car', 'truck', 'truck', 'bike', 'walk', 'car', 'van', 'bike', 'walk', 'car', 'van', 'car', 'truck' ];
    
    const sumObj = data.reduce((obj, item) => {
      // 避免没有的情况
      if(!obj[item]) {
        obj[item] = 0;
      }
      obj[item]++;
      return obj;
    }, {})
    console.log(sumObj);

  </script>
</body>
</html>
